Shallow decay phase of X-ray afterglows

R. Sato, K. Ioka, K. Toma, T. Nakamura, Jun Kataoka, N. Kawai, T. Takahashi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

We investigated the characteristics of the shallow decay phase in the early X-ray afterglows of GRBs observed by Swift X-Ray Telescope (XRT) during the period of January 2005 to December 2006. We found that the intrinsic break time at the shallow-to-normal decay transition in the X-ray light curve T brk0 is moderately well correlated with the isotropic X-ray luminosity in the end of the shallow decay phase (LX,end) as Tbrk0=(9.39±0.64)×103s(L X,end/1047ergsṡs-1) -0.71±0.03. Using Tbrk0-L X,end relation we have determined the pseudo redshifts of 33 GRBs. We compared the pseudo redshifts of 11 GRBs with measured redshifts and found the rms error to be 0.17 in logz. From this pseudo redshift, we estimate that ∼15% of the Swift GRBs have z>5. The advantages of this distance indicator is that (1) it requires only X-ray afterglow data while other methods such as Amati and Yonetoku correlations require the peak energy (Ep) of the prompt emission, (2) the redshift is uniquely determined without redshift degeneracies unlike the Amati correlation, and (3) the redshift is estimated in advance of deep follow-ups so that possible high redshift GRBs might be selected for detailed observations.

Original languageEnglish
Title of host publicationAIP Conference Proceedings
Pages32-35
Number of pages4
Volume1000
DOIs
Publication statusPublished - 2008
Externally publishedYes
EventSanta Fe Conference on Gamma-Ray Bursts 2007, GRB 2007 - Santa Fe, NM
Duration: 2007 Nov 52007 Nov 9

Other

OtherSanta Fe Conference on Gamma-Ray Bursts 2007, GRB 2007
CitySanta Fe, NM
Period07/11/507/11/9

Fingerprint

afterglows
decay
x rays
light curve
luminosity
telescopes
estimates
energy

Keywords

  • X-ray afterglows

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Sato, R., Ioka, K., Toma, K., Nakamura, T., Kataoka, J., Kawai, N., & Takahashi, T. (2008). Shallow decay phase of X-ray afterglows. In AIP Conference Proceedings (Vol. 1000, pp. 32-35) https://doi.org/10.1063/1.2943476

Shallow decay phase of X-ray afterglows. / Sato, R.; Ioka, K.; Toma, K.; Nakamura, T.; Kataoka, Jun; Kawai, N.; Takahashi, T.

AIP Conference Proceedings. Vol. 1000 2008. p. 32-35.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Sato, R, Ioka, K, Toma, K, Nakamura, T, Kataoka, J, Kawai, N & Takahashi, T 2008, Shallow decay phase of X-ray afterglows. in AIP Conference Proceedings. vol. 1000, pp. 32-35, Santa Fe Conference on Gamma-Ray Bursts 2007, GRB 2007, Santa Fe, NM, 07/11/5. https://doi.org/10.1063/1.2943476
Sato R, Ioka K, Toma K, Nakamura T, Kataoka J, Kawai N et al. Shallow decay phase of X-ray afterglows. In AIP Conference Proceedings. Vol. 1000. 2008. p. 32-35 https://doi.org/10.1063/1.2943476
Sato, R. ; Ioka, K. ; Toma, K. ; Nakamura, T. ; Kataoka, Jun ; Kawai, N. ; Takahashi, T. / Shallow decay phase of X-ray afterglows. AIP Conference Proceedings. Vol. 1000 2008. pp. 32-35
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